Method of coding and decoding still picture

Abstract

A method of coding and decoding a still picture is provided. The method of coding and decoding a still image includes: constructing a coded data configured with a region consisting of a first information expressible in bit and a second information expressible in byte by using separate output buffers; and separately allocating a first output buffer for the first information and a second output buffer for the second information, and decoding the coded data.

Description

[0001] This application claims the benefit of the Korean Patent Application No. 10-2004-0105723, filed on Dec. 14, 2004, which is hereby incorporated by reference as if fully set forth herein. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a method of coding and decoding still picture. [0004] 2. Description of the Related Art [0005] Various kinds of mobile terminals have been provided. Although the mobile terminals get miniaturized, the resolution of screen is increasing and the number of colors expressible per pixel is increasing. Also, high-quality displays tend to be mounted. [0006] In the mobile terminals, user interface (UI) is developed toward three-dimensional image and animation UI, as well as simple image. Accordingly, there is an increasing demand for memory space for recording an image stored in the mobile terminal and playing it for the user interface. Developments of a dedicated compression codec for picture of the U...

AI Technical Summary

Benefits of technology

[0014] An object of the present invention is to provide a method of coding and decoding still picture, which can reduce the number of times of memory access and code and decode an image data at a small amount of computation.

[0015] Another object of the present invention is to provide a method of coding and decoding still picture, which can be applied to a UI codec requiring a fast coding speed by decoding an image data coded at a small number of times of memory access and a small amount of computation.

[0016] A further another aspect of the present invention is to provide a method of coding and decoding still image, which can be applied to a UI codec requiring a fast coding performance by modifying a coding stream structure. In the method, an amount of computation for pointer calculation is reduced, the number of memory access is reduced, and the still image data can be processed by a simple consecutive shifting operation, thereby providing a fast decoding speed.

[0020] According to the present invention, the picture can be fast displayed by coding and decoding UI pictures such as a background picture and icon in a mobile phone, and a memory space can also be reduced. The case of using a 16-bit external bus and the case of using a 32-bit external bus can be designed in ARM and can be selectively applied. The present invention can be applied to other codec as well as the ARM. Further, a decoder having the fast decoding and display performance can be implemented by reducing the number of times of memory access.

Problems solved by technology

For most of the mobile phones, for example a portable phone, a low-performance central processing unit (CPU) such as an advanced RISC machine 7 (ARM7) and ARM9 controls the UI and thus it is difficult to use a codec such as JPEG having a large amount of computation.

However, such a method causes problems in an environment with restricted memory and resource such as a mobile terminal.

Specifically, in the case of the ARM that is widely used as a processor in the mobile terminal, these factors will degrade the decoding and display speed of UI picture.

Images